Wiper blade

Abstract

A wiper blade of a wiper device is composed of a primary lever driven by an wiper arm to swing on a windshield, a pair of bowed secondary levers connected to the primary lever to extend on a side of the primary lever facing a direction of the swinging and a pair of bowed yoke levers connected to the primary lever to extend on the side of the primary lever opposite to the secondary levers and a rubber blade supported by the yoke levers. Thus, the primary lever, the secondary levers and the yoke levers are disposed in the same plane above the windshield, thereby reducing the frontal projected area relative to air flow. Each of the secondary levers is connected jointly with one of the yoke levers to rotate on a shaft fixed to the primary lever.

What is claimed is: 
     
       1. A wiper blade of a wiper device for a vehicle windshield including a wiper motor and a wiper arm driven by said wiper motor, said wiper blade comprising: a first lever, rotatably connected to said wiper arm, for swinging on said windshield alternately in a first direction and a second direction opposite said first direction;   a second lever extending on a first side of said first lever facing the first direction of swinging of said first lever, said second lever rotatably connected to an end of said first lever on an axis;   a third lever extending on a second side of said first lever facing the second direction of swinging of said first lever, said third lever rotatably connected to the end of said first lever on said axis; and   a rubber blade supported by said second and third levers.   
     
     
       2. The wiper blade as claimed in claim 1 further comprising a fourth lever disposed between said second lever and said rubber blade for supporting said rubber blade at an end thereof. 
     
     
       3. The wiper blade as claimed in claim 1, wherein each of said first, second, third levers is made of resinous material. 
     
     
       4. The wiper blade as claimed in claim 3, wherein said first, second and third levers are rotatably connected by a shaft jointly.   
     
     
       5. The wiper blade as claimed in claim 4, wherein said shaft has engagement portions at opposite ends thereof in engagement with corresponding portions of said first, second and third levers.   
     
     
       6. The wiper blade as claimed in claim 5, wherein said shaft is made of metal and covered by said first, second and third levers.   
     
     
       7. The wiper blade as claimed in claim 1, wherein said second and third levers are bowed toward a longitudinal center of said rubber blade to support said rubber blade in a straight line. 
     
     
       8. The wiper blade as claimed in claim 7, wherein said first lever has a member connected to said wiper arm disposed above the longitudinal center of said rubber blade.   
     
     
       9. A wiper blade of a wiper device for a curved windshield including a wiper motor and a wiper arm driven by said wiper motor, said wiper blade comprising: a flexible rubber blade;   a primary lever rotatably connected to said wiper arm for swinging said rubber blade with a pressure on said windshield, said primary lever swinging alternately in a first direction and a second direction opposite said first direction;   a pair of bowed secondary levers extending on a side of said primary lever facing said first direction of swinging, each of said secondary levers rotatably connected to longitudinally opposite ends of said primary lever; and   a plurality of bowed yoke levers extending on the side of said primary lever opposite to said secondary levers, each of said yoke levers rotatably connected to one of said secondary levers for supporting said rubber blade so as to move along said curved windshield.   
     
     
       10. The wiper blade as claimed in claim 9 further comprising a second yoke lever extending on the same side of said primary lever as said secondary levers extend, said second yoke lever rotatably connected to one of said yoke levers at an outer end thereof to support an outer end of said rubber blade. 
     
     
       11. The wiper blade as claimed in claim 10 further comprising a third yoke lever extending on the same side of said primary lever as said yoke levers extend, said third yoke lever rotatably connected to an outer end of said second levers to support an outer end of said rubber blade. 
     
     
       12. The wiper blade as claimed in claim 9, wherein each of said primary lever, secondary levers and yoke levers are made of resinous material.   
     
     
       13. The wiper blade as claimed in claim 9, wherein each end of said yoke levers is disposed on the longitudinal center line of said rubber blade.   
     
     
       14. The wiper blade as claimed in claim 9, wherein at least one of said primary lever, secondary levers and yoke levers has a wing member for preventing said rubber blade from lifting. 
     
     
       15. The wiper blade as claimed in claim 14, said wing member is an integral portion of said one of said primary lever, secondary levers and yoke levers. 
     
     
       16. The wiper blade as claimed in claim 15, said primary lever overlaps with said secondary levers at ends thereof, and said secondary levers respectively overlap with said yoke levers at ends thereof.